/*
 * Copyright (C) 2009 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.common.collect;

import static com.google.common.base.Preconditions.checkNotNull;

import com.google.common.annotations.GwtCompatible;
import java.util.Map;

/**
 * An implementation of {@link ImmutableTable} that holds a single cell.
 *
 * @author Gregory Kick
 */
@GwtCompatible
class SingletonImmutableTable<R, C, V> extends ImmutableTable<R, C, V> {
    final R singleRowKey;
    final C singleColumnKey;
    final V singleValue;

    SingletonImmutableTable(R rowKey, C columnKey, V value) {
        this.singleRowKey = checkNotNull(rowKey);
        this.singleColumnKey = checkNotNull(columnKey);
        this.singleValue = checkNotNull(value);
    }

    SingletonImmutableTable(Cell<R, C, V> cell) {
        this(cell.getRowKey(), cell.getColumnKey(), cell.getValue());
    }

    @Override
    public ImmutableMap<R, V> column(C columnKey) {
        checkNotNull(columnKey);
        return containsColumn(columnKey) ? ImmutableMap.of(singleRowKey, singleValue) : ImmutableMap.<R, V>of();
    }

    @Override
    public ImmutableMap<C, Map<R, V>> columnMap() {
        return ImmutableMap.of(singleColumnKey, (Map<R, V>) ImmutableMap.of(singleRowKey, singleValue));
    }

    @Override
    public ImmutableMap<R, Map<C, V>> rowMap() {
        return ImmutableMap.of(singleRowKey, (Map<C, V>) ImmutableMap.of(singleColumnKey, singleValue));
    }

    @Override
    public int size() {
        return 1;
    }

    @Override
    ImmutableSet<Cell<R, C, V>> createCellSet() {
        return ImmutableSet.of(cellOf(singleRowKey, singleColumnKey, singleValue));
    }

    @Override
    ImmutableCollection<V> createValues() {
        return ImmutableSet.of(singleValue);
    }

    @Override
    SerializedForm createSerializedForm() {
        return SerializedForm.create(this, new int[] {0}, new int[] {0});
    }
}
